The use of fiber-reinforced composites poses significant environmental problems because most end-of-life composite waste is sent to landfills, and effective recycling technologies have drawn research attention. Our previous study demonstrated that chemical treatments at atmospheric pressure – depolymerization (benzyl alcohol/K3PO4 at 200 °C) and acid digestion (acetic acid/H2O2 at 110 °C) – were both effective for dissolution of amine-cured neat epoxy. In this paper, depolymerization and acid digestion were applied to amine/epoxy composites, including composites produced from lab-made and aerospace prepregs, and commercial composite waste. Findings indicated that acid digestion was more effective for highly crosslinked amine/epoxy composites than depolymerization. Furthermore, digestion occurred via reaction steps of oxygen atom transfer to the aniline groups and then bond cleavage, resulting in recovery of near-virgin quality fibers at faster dissolution rates and lower temperatures. The relationship between epoxy functionality, fiber bed architecture, fiber reinforcement, laminate thickness and matrix dissolution rate were investigated, and key parameters affecting the dissolution rate were identified. Data showed that the major rate-limiting factor for acid digestion was the diffusion rate, rather than the chemical reaction rate. Two strategies to enhance the diffusion rate – pre-treatment and mechanical shredding – were evaluated, and both were effective. Polymer matrices in pre-treated and shredded composites were homogeneously decomposed in 1 h.
Polymer Degradation and Stability – Elsevier
Published: Jul 1, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera